1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor device. In particular, the present invention relates to a manufacturing method of a semiconductor device which inputs and outputs data by wireless communication.
2. Description of the Related Art
A manufacturing method of a semiconductor device provided with a semiconductor integrated circuit over a flexible substrate has been proposed. In this method, first, a plurality of semiconductor integrated circuits is formed using a thin film transistor over a first substrate, which is not flexible and is formed from a thick glass or the like. The plurality of the semiconductor integrated circuits is formed while keeping a predetermined distance from each other over the first substrate. The plurality of the semiconductor integrated circuits is transferred from the first substrate to a flexible second substrate. The plurality of the semiconductor integrated circuits is all transferred from the first substrate to the second substrate concurrently; therefore, also over the second substrate, the plurality of the semiconductor integrated circuits is arranged while keeping the predetermined distance from each other. Thereafter, the second substrate is divided to be separated into individual semiconductor integrated circuits, thereby obtaining a plurality of semiconductor devices (refer to description in Patent Document 1: Japanese Published Patent Application No. 2005-311333). The predetermined distance becomes a margin for division (hereinafter, referred to as a division margin or a scribe margin) in obtaining the plurality of the semiconductor devices by dividing the second substrate.
In manufacturing the plurality of the semiconductor integrated circuits over the first substrate, an insulating film formed over an entire surface of the first substrate is used for an insulating film such as an interlayer insulating film included in the plurality of the semiconductor integrated circuits. Therefore, the insulating film exists between the plurality of the semiconductor integrated circuits over the first substrate. By a conventional manufacturing method of a semiconductor device, the plurality of the semiconductor integrated circuits is transferred all together from the first substrate to the second substrate. Therefore, also over the second substrate, the insulating film exists between the plurality of the semiconductor integrated circuits. Accordingly, when the second substrate is divided to be separated into individual semiconductor integrated circuits, a structure is obtained, in which the insulating film included in the semiconductor integrated circuits is exposed in a cross section formed by the division. Therefore, even if a protective layer is formed to cover the semiconductor integrated circuits to seal the semiconductor integrated circuits, there is a problem that an external impurity intrudes in the semiconductor integrated circuits through the insulating film. Thus, it has been difficult to ensure reliability of the semiconductor integrated circuits.